The Tottenham manager saw his side crash to a 1-0 loss to Premier League strugglers West Bromwich Albion.
Spurs slumped to a shock 1-0 defeat at home to West Brom on Sunday, and it left the man in charge of the North Londoners fuming after a thoroughly toothless display.
Mauricio Pochettino was famous for employing a high energy pressing game at Southampton that would give sides little time to get comfortable on the ball, and give quick turnarounds in areas where his side could immediately pose a significant threat to their opponents.
But against West Brom on Sunday, Tottenham failed to provide any kind of attacking threat in West Brom's defensive third at all, registering just one shot on target and creating very few openings, only for James Morrison to score a late header that would go on to earn his side all three points.
Unsurprisingly, Tottenham's Argentine boss was angry with his team's performance, and highlighted several issues when he spoke to Spurs TV after the game.
"I am angry or disappointed - I don't know the best word to show my feelings," said Pochettino. "We had a bad day.
“We played with a very slow tempo at the beginning of the game and it was difficult after that to go and win,.
“We need to analyse why because we had a very bad day. Maybe we didn’t deserve to lose the game but we made a mistake from a set-piece and after that the team never showed the belief to get the three points.
“I’m surprised, very disappointed and we need to understand why.
“I think the reason is we played very slowly at the beginning and we need to move the ball faster. After that, without the ball, we need to be more aggressive.
“We have another game on Wednesday, we need to be focused and to show a different attitude.”
Spurs will have the chance to make amends in midweek when they take on Championship side Nottingham Forest in the League Cup, before the crunch North London derby at the Emirates in next Saturday's late kick off.
Tottenham fans will certainly expect a better performance against their fierce rivals than the White Hart Lane outfit managed this weekend.